Motor monitoring device

Abstract

A motor monitoring device according to one embodiment of the present disclosure, which can easily ascertain the state of a motor, is provided with: a rotational speed acquisition unit that acquires the rotational speed of a motor that operates in accordance with an operation program; an output value acquisition unit that acquires an output value of the motor; and a graph display unit that draws a mark indicating a combination of the rotational speed and the output value in a graph region in which one axis is the rotational speed and the other axis is the output value, the graph display unit having: a unit region setting unit that sets the rotational speed in the graph region and sets the output value in the graph region; the setting unit is used for setting a plurality of unit areas for dividing the chart area into lattices; and a mode changing unit that changes the display mode of the mark for each unit region on the basis of a predetermined index.

Description

Technical Field

[0001] The invention relates to a motor monitoring device. Background Art

[0002] For example, in a motor such as a spindle motor of a machine tool, whose load may vary greatly, if the state of heavy load continues, heat may be accumulated and overheated. In such a motor, various time ratings can be set so that it can operate without overheating under specific conditions. As time ratings, for example, JIS-C4034-1 stipulates a continuous rating that can operate continuously, a short-time rating that can operate for a certain time (load time) from room temperature, and a repeated rating that can operate for a certain time (load time rate) within a specified cycle time.

[0003] It has also been proposed to estimate the time until the motor overheats while maintaining the current operating state (see, for example, Patent Document 1). If the time until overheating is known, it is possible to determine whether the current processing can be continued to the end.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5628994 Summary of the invention

[0007] Problems to be solved by the invention

[0008] It is not easy to understand the safety and margin of the motor's operation by simply estimating the time until overheating. Specifically, when adjusting the setting value of the motor speed and the like in order to minimize the margin for overheating and maximize efficient processing, it is not easy to determine to what extent the setting value should be increased or decreased. Therefore, a technology that can easily understand the state of the motor is desired.

[0009] Means for solving problems

[0010] A motor monitoring device according to one embodiment of the present invention comprises: a rotational speed acquisition unit, which acquires the rotational speed of a motor that operates according to an action program; an output value acquisition unit, which acquires the output value of the motor; a graph display unit, which depicts a mark representing a combination of the rotational speed and the output value in a graph area, in which one axis is set to the rotational speed and the other axis is set to the output value, and the graph display unit comprises: a unit area setting unit, which sets a plurality of unit areas that divide the graph area into a grid; and a mode changing unit, which changes the display mode of the mark according to the unit area based on a specified indicator.

[0011] Effects of the Invention

[0012] According to the present disclosure, the state of the motor can be easily grasped. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a block diagram showing the configuration of a machine tool including the motor monitoring device according to the first embodiment of the present disclosure.

[0014] Figure 2 is an example Figure 1 A table of information stored in the information storage unit of the motor monitoring device.

[0015] Figure 3 is an example Figure 1 Diagram of the display of a motor monitoring device. DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Figure 1 1 is a block diagram showing the configuration of a machine tool 1 including a motor monitoring device according to a first embodiment of the present disclosure.

[0017] The machine tool 1 includes: a numerical controller 10 as an embodiment of the motor monitoring device of the present invention, a spindle motor 20, a rotation speed detector 21 for detecting the rotation speed of the spindle motor 20, a current detector 22 for detecting the current of the spindle motor 20, a temperature detector 23 for detecting the winding temperature of the spindle motor 20, a display device 30 for displaying a screen according to the numerical controller 10, and an input device 40 for a user to input to the numerical controller 10.

[0018] The numerical control device 10 controls the operation of the spindle motor 20 and other structural elements according to the action program (referred to as a machining program in the numerical control device) so that the workpiece can be processed as required in the machine tool 1. The numerical control device 10 has a memory, a processor (CPU), an input / output interface, etc., and can be implemented by one or more computer devices that execute appropriate control programs. The structural elements of the numerical control device 10 described below are obtained by classifying the functions of the numerical control device 10, and may not be clearly distinguished in the physical structure and program structure.

[0019] The spindle motor 20 is typically a motor that drives a cutting tool or a workpiece to rotate. As described above, the spindle motor 20 operates according to an operation program, but the load may vary regardless of the rotation speed depending on the processing conditions. The rotation speed detector 21, the current detector 22, and the temperature detector 23 can be respectively composed of known sensors.

[0020] The display device 30 is a well-known display that displays according to the signal input from the numerical controller 10. The display device 30 may be configured integrally with the numerical controller 10. The input device 40 is a device for the user to input information to the numerical controller 10, and may be a well-known structure such as a keyboard or a mouse. The input device 40 may be configured integrally with the numerical controller 10. In addition, the input device 40 may be configured integrally with the display device 30. Specifically, the display device 30 and the input device 40 may be a single input / output device such as a touch panel.

[0021] In this embodiment, the numerical control device 10 includes: a program storage unit 11; a motor control unit 12 that controls the operation of a motor that drives a drive shaft of the machine tool 1 including a spindle motor 20; and a motor monitoring unit 13 that performs the function of the motor monitoring device of the present disclosure.

[0022] The program storage unit 11 stores an action program executed in the machine tool 1. The action program includes a plurality of program blocks that respectively specify unit actions of the machine tool 1. Each program block includes one or more characters composed of a combination of a plurality of characters (letters). Generally, each program block is initially assigned a serial number for identifying the program block.

[0023] The motor control unit 12 controls the spindle motor 20 and other drive axis motors of the machine tool 1 according to the operation program, thereby executing the machining process described in the operation program. The configuration of the motor control unit 12 is the same as that of a known numerical control device, so detailed description is omitted.

[0024] The motor monitoring unit 13 includes a program acquisition unit 131 , a rotation speed acquisition unit 132 , an output value acquisition unit 133 , an estimated time calculation unit 134 , an information storage unit 135 , and a graph display unit 136 .

[0025] The program acquisition unit 131 acquires an operation program that specifies an operation to be monitored by the spindle motor 20 from the program storage unit 11. That is, the program acquisition unit 131 develops the target operation program in the work memory.

[0026] The rotation speed acquisition unit 132 acquires the rotation speed of the spindle motor 20 from the rotation speed detector 21. The rotation speed acquisition unit 132 may acquire the rotation speed of the spindle motor 20 via the motor control unit 12.

[0027] The output value acquisition unit 133 acquires output values ​​of the spindle motor 20, such as the current value, the power value, and the torque value. In the present embodiment, the output value acquisition unit 133 attempts to acquire the current value of the spindle motor 20 from the current detector 22 and uses the power value calculated from the current value as the output value, but the output value acquisition unit 133 may be configured to directly use the detection value such as the current value as the output value. The output value acquisition unit 133 may also acquire the output value or the value required to calculate the output value from the motor control unit 12. In addition, the output value acquisition unit 133 may also acquire two or more output values.

[0028] The estimated time calculation unit 134 calculates the estimated time until the spindle motor 20 reaches the overheating temperature if the rotation speed and output value at that time are maintained based on the winding temperature of the spindle motor 20 obtained from the temperature detector 23 and the current value or output value obtained by the output value acquisition unit 133 .

[0029] The information storage unit 135 stores the operation information related to the operation state of the spindle motor 20 at fixed time intervals. The operation information includes the rotation speed and the output value, and can include the position information of the corresponding command of the action program, and the modal information specifying the action of the spindle motor 20. As the position information of the action program, the sequence number, the line number, the program block number, etc. can be cited. As the modal information, the command extracted from the action program (not limited to the one that directly specifies the action of the spindle motor 20, such as the command that specifies the tool and may affect the action of the spindle motor 20) and the set value of the numerical control device 10 such as the upper limit value of the acceleration can be cited. In addition, the information storage unit 135 can also pre-calculate the load level and the like used in the graph display unit 136 as described later, and save it as an element of the operation information.

[0030] The time interval for saving the operation information may be a predetermined fixed time, or a time obtained by dividing the processing time estimated from the operation program by a predetermined number of the operation information set in advance. In addition, the information storage unit 135 may also be configured to save the operation information at a time interval specified by the user via the input device 40 or the like. Figure 2 The content of the operation information stored in the information storage unit 135 is illustrated. As can be seen from the figure, the information storage unit 135 can be configured to create a relational database with the acquisition time of the operation information as data or the serial number as a unique key. In addition, "-" in the figure means that the corresponding information cannot be calculated or does not exist.

[0031] like Figure 3As illustrated, the graph display unit 136 displays a graph in which marks representing combinations of rotation speeds and output values ​​are drawn in a graph area in which one axis is set as the rotation speed and the other axis is set as the output value. The graph display unit 136 includes a unit area setting unit 1361, a load area setting unit 1362, a mode changing unit 1363, a margin setting unit 1364, and a suggestion display unit 1365.

[0032] The unit area setting unit 1361 sets a plurality of unit areas for dividing the graph area into a grid. Figure 3 In the figure, the boundary of the unit area is indicated by a dotted line. The boundary line of the unit area is used to explain the unit area, and may not exist in the screen actually displayed on the display device 30. The unit area setting unit 1361 can also determine the size of the unit area based on the user's input. In this way, the amount of information required for the mode change unit 1363 to change the display mode of the mark can be ensured, and a sufficient number of unit areas can be set. The unit area setting unit 1361 can be configured so that the user can specify the length of the unit area of ​​each axis, or can be configured so that the number of unit areas (number of divisions) of each axis can be specified.

[0033] The load region setting unit 1362 divides the graph region into a plurality of load regions with different load levels. The load regions may be bounded by combinations of rotation speeds and output values ​​that are considered to have equal loads on the spindle motor 20, such as various rated values. Figure 3 In the diagram, the graph area is divided into four areas: a continuous load area where continuous operation is possible, a short-time load area where intermittent operation is possible, a maximum load area where temporary operation is possible, and an inoperable area where short-time operation is not permitted, based on the continuous rated value, time rated value, and maximum output indicated by double-dashed lines, respectively. In addition, the boundary lines of these load areas may not exist on the screen actually displayed on the display device 30.

[0034] The mode change unit 1363 changes the display mode of the mark in a unit area according to the specified index. Thus, further information can be displayed on a two-dimensional graph, and the state of the spindle motor 20 can be easily understood to the user. As a change in the mode of the mark based on the mode change unit 1363, for example, a change in color corresponding to the value of the index such as blue, yellow, and red, a change in concentration or brightness corresponding to the value of the index, a change in the length or size of the mark corresponding to the value of the index, etc. can be cited. That is, it is preferred that the mode change unit 1363 changes the display mode of the mark according to the specified rule so that the size of the value of the index can be identified.

[0035] As an index for determining the marking method, there can be cited the frequency of occurrence of the combination of the rotation speed and the output value in each unit area, for example, the load level determined by the area set by the load area setting unit 1362, and the estimated time until the overheat temperature is reached calculated by the estimated time calculation unit 134. The method changing unit 1363 can also change the plurality of marking methods according to different indexes.

[0036] When the marking method is changed according to the frequency of occurrence of each unit area of ​​the combination of the rotation speed and the output value, the method change unit 1363 may also change the display method of the marking according to the ratio of the number of operation information belonging to the unit area to the total number of operation information within a specified time range or the number of operation information with a value of the output value (excluding the number of operation information with a zero output value). In this way, by setting it as a relative value instead of an absolute number of frequencies, the marking method change can be increased, so that the user can more easily grasp the state of the spindle motor 20. The time range for counting the frequency of occurrence may be set based on the time when the acceleration or deceleration of the spindle motor 20 is completed, or may be the entire range from the start of the operation of the spindle motor 20 to the end of the operation.

[0037] The margin setting unit 1364 sets a margin, which is an allowable range of distances from the boundary of the load region for a combination of the rotation speed and the output value. Figure 3 The boundary of the allowable range is indicated by a single dot-dashed line. In the example shown in the figure, the allowable range is set by axis, so the boundary line is a square, but the allowable range can also be set as a two-dimensional distance taking into account the two axes in a circular manner. In addition, the boundary of the allowable range may not exist in the screen actually displayed on the display device 30.

[0038] The advice display unit 1365 adds an advice display, which advises changing the operating conditions of the spindle motor 20 according to the load level, to the mark. Figure 3 In the example, a mark of a load level exceeding the time rating is added with an arrow pointing to the lower left for suggesting a load reduction as a suggestion display, and a mark of a load level less than the time rating is added with an arrow pointing to the upper right for suggesting an load increase as a suggestion display. In addition, the output value of the spindle motor 20 is not a value set by itself, but increases mainly as the rotation speed of the spindle motor 20 increases, so as a result, the combination of the rotation speed and the output value moves in the direction of the arrow of the suggestion display. The suggestion display unit 1365 can also be configured to start an editor that displays the suggestion display in a manner that the user can select, and when the suggestion display is selected, the corresponding part of the action program is displayed in an editable manner.

[0039] The suggestion display unit 1365 may also be configured to add a suggestion display when the distance of the combination of the rotational speed and the output value from the boundary of the load area is greater than the margin. If it is recommended to increase the output when the combination of the rotational speed and the output value is close to the boundary of the load area, the combination of the rotational speed and the output value after the change may exceed the boundary of the load area. Therefore, it is preferable to recommend a change in the operating conditions of the spindle motor 20 only when there is a margin in the distance to the boundary of the load area. When it is recommended to reduce the output, it is not necessary to consider the margin from the perspective of safety, but if the output is reduced, there may be a disadvantage of increasing the processing time. Therefore, when approaching the boundary of the load area, it is not necessary to actively recommend reducing the output.

[0040] The numerical control device 10 of this embodiment has: a chart display unit 136, which has a unit area setting unit 1361 for setting a chart area divided into a plurality of unit areas in a grid shape, and a mode changing unit 1363 for changing the display mode of the mark by unit area according to a specified indicator, so that the user can understand the status of the spindle motor 20 in more aspects.

[0041] The embodiments of the present disclosure are described above, but the present invention is not limited to the embodiments described above. In addition, the effects described in the embodiments described above are merely examples of preferred effects produced by the present invention, and the effects of the present invention are not limited to the effects described in the embodiments described above.

[0042] The motor monitoring device of the present disclosure can be set independently of the numerical control device that controls the machine tool, and can also confirm the status of motors other than the spindle motor of the machine tool, such as the motor of the kneading machine. As an example, the motor monitoring device of the present disclosure can also be a device in which the functions of the motor monitoring unit of the above embodiment are added to a management computer that manages one or more numerical control devices, such as a control device such as a kneading machine, or a management computer that manages such a control device. In addition, in the motor monitoring device of the present disclosure, the load area setting unit, the margin setting unit, and the suggestion display unit are arbitrary structures.

[0043] Description of Reference Numerals

[0044] 1 Machine tools

[0045] 10 Numerical control device (motor monitoring device)

[0046] 11 Program storage unit

[0047] 12 Motor control unit

[0048] 13 Motor monitoring unit

[0049] 131 Program Acquisition Department

[0050] 132 Speed ​​acquisition unit

[0051] 133 Output value acquisition unit

[0052] 134 Estimated time calculation unit

[0053] 135 Information Storage Department

[0054] 136 Graphic display unit

[0055] 1361 Unit Area Setting Department

[0056] 1362 Load area setting unit

[0057] 1363 Method Change Department

[0058] 1364 Remaining quantity setting unit

[0059] 1365 Recommended Display Department

[0060] 20 Spindle motor

[0061] 21. Speed ​​detector

[0062] 22 Current detector

[0063] 23. Temperature detector

[0064] 30 Display device

[0065] 40 Input device.

Claims

1. A motor monitoring device, characterized in that: have: a rotation speed acquisition unit that acquires the rotation speed of the electric motor that operates according to the operation program; an output value acquiring unit that acquires an output value of the motor; a graph display unit that draws a mark indicating a combination of the rotation speed and the output value in a graph area, wherein one axis of the graph area is set to the rotation speed and the other axis is set to the output value, The graph display unit has: a unit region setting unit for setting a plurality of unit regions for dividing the graph region into a grid; A mode changing unit changes a display mode of the mark for each unit area based on a predetermined index.

2. The motor monitoring device according to claim 1, characterized in that: The motor monitoring device further comprises: an information storage unit which stores the rotation speed and the output value at fixed time intervals; The mode changing unit changes the display mode of the mark according to the appearance frequency of the combination of the rotation speed and the output value in each of the unit areas.

3. The motor monitoring device according to claim 2, characterized in that: The mode changing unit changes the display mode of the mark based on the occurrence frequency of the combination of the rotation speed and the output value within a predetermined time range, with the acceleration or deceleration of the electric motor being completed as a reference.

4. The motor monitoring device according to claim 2, characterized in that: The mode changing unit changes the display mode of the mark according to the frequency of occurrence of the combination of the rotation speed and the output value in the entire range from the start of operation to the end of operation of the electric motor.

5. The motor monitoring device according to any one of claims 1 to 4, characterized in that: The mode changing unit changes the display mode of the mark so that the load level of the unit area can be identified.

6. The motor monitoring device according to any one of claims 1 to 5, characterized in that: The unit area setting unit determines a size of the unit area according to a user input.

7. The motor monitoring device according to any one of claims 1 to 6, characterized in that: The chart display unit also has: a load region setting unit that divides the graph region into a plurality of load regions having different load levels; An advice display unit adds an advice display to the mark, the advice display suggesting a change in an operating condition of the motor according to a load level.

8. The motor monitoring device according to claim 7, characterized in that: The graph display unit further includes a margin setting unit for setting a margin, which is an allowable range of distances from a boundary of a load region of the rotation speed and the output value. The advice display unit adds the advice display when the distance from the boundary of the load region of the combination of the rotation speed and the output value is equal to or larger than the margin.

9. The motor monitoring device according to claim 7 or 8, characterized in that: The motor monitoring device further includes an estimated time calculation unit that calculates an estimated time until the motor reaches an overheating temperature while maintaining the rotation speed and the output value at that time. The mode changing unit changes a display mode of the mark according to the estimated time.

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